juce_OptionalScopedPointer.h

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/*
  ==============================================================================
 
   This file is part of the JUCE library.
   Copyright (c) 2022 - Raw Material Software Limited
 
   JUCE is an open source library subject to commercial or open-source
   licensing.
 
   The code included in this file is provided under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license. Permission
   To use, copy, modify, and/or distribute this software for any purpose with or
   without fee is hereby granted provided that the above copyright notice and
   this permission notice appear in all copies.
 
   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.
 
  ==============================================================================
*/
 
namespace juce
{
 
//==============================================================================
template <class ObjectType>
class OptionalScopedPointer
{
public:
    //==============================================================================
    OptionalScopedPointer() = default;

    OptionalScopedPointer (ObjectType* objectToHold, bool takeOwnership)
        : object (objectToHold),
          shouldDelete (takeOwnership)
    {
    }

    OptionalScopedPointer (OptionalScopedPointer&& other) noexcept
        : object (std::move (other.object)),
          shouldDelete (std::move (other.shouldDelete))
    {
    }

    explicit OptionalScopedPointer (std::unique_ptr<ObjectType>&& ptr) noexcept
        : OptionalScopedPointer (ptr.release(), true)
    {
    }

    explicit OptionalScopedPointer (ObjectType& ref) noexcept
        : OptionalScopedPointer (std::addressof (ref), false)
    {
    }

    OptionalScopedPointer& operator= (OptionalScopedPointer&& other) noexcept
    {
        swapWith (other);
        other.reset();
        return *this;
    }

    ~OptionalScopedPointer() noexcept
    {
        reset();
    }
 
    //==============================================================================
    operator ObjectType*() const noexcept                    { return object.get(); }

    ObjectType* get() const noexcept                         { return object.get(); }

    ObjectType& operator*() const noexcept                   { return *object; }

    ObjectType* operator->() const noexcept                  { return object.get(); }
 
    //==============================================================================
    ObjectType* release() noexcept                                  { return object.release(); }

    void reset() noexcept
    {
        if (! shouldDelete)
            object.release();
        else
            object.reset();
    }

    void clear()                                                    { reset(); }

    void set (ObjectType* newObject, bool takeOwnership)
    {
        if (object.get() != newObject)
        {
            reset();
            object.reset (newObject);
        }
 
        shouldDelete = takeOwnership;
    }

    void setOwned (ObjectType* newObject)
    {
        set (newObject, true);
    }

    void setNonOwned (ObjectType* newObject)
    {
        set (newObject, false);
    }

    bool willDeleteObject() const noexcept                          { return shouldDelete; }
 
    //==============================================================================
    void swapWith (OptionalScopedPointer<ObjectType>& other) noexcept
    {
        std::swap (other.object, object);
        std::swap (other.shouldDelete, shouldDelete);
    }
 
private:
    //==============================================================================
    std::unique_ptr<ObjectType> object;
    bool shouldDelete = false;
};
 
} // namespace juce